J/AJ/135/1225 Parameters of the local white dwarfs (Holberg+, 2008)
A new look at the local white dwarf population.
Holberg J.B., Sion E.M., Oswalt T., McCook G.P., Foran S., Subasavage J.P.
<Astron. J., 135, 1225-1238 (2008)>
=2008AJ....135.1225H 2008AJ....135.1225H
ADC_Keywords: Parallaxes, trigonometric ; Stars, white dwarf ; Spectral types
Keywords: stars: distances - stars: statistics - techniques: photometric -
white dwarfs
Abstract:
We have conducted a detailed new survey of the local population of
white dwarfs lying within 20pc of the Sun. A new revised catalog of
local white dwarfs containing 122 entries (126 individual degenerate
stars) is presented. This list contains 27 white dwarfs not included
in a previous list from 2002, as well as new and recently published
trigonometric parallaxes. In several cases new members of the local
white dwarf population have come to light through accurate photometric
distance estimates. In addition, a suspected new double degenerate
system (WD 0423+120) has been identified. The 20pc sample is
currently estimated to be 80% complete. Using a variety of recent
spectroscopic, photometric, and trigonometric distance determinations,
we re-compute a space density of 4.8±0.5x10-3pc-3
corresponding to a mass density of 3.2±0.3x10-3M☉pc-3
from the complete portion of the sample within 13pc. We find an
overall mean mass for the local white dwarfs of 0.665M☉, a value
larger than most other non-volume-limited estimates. Although the
sample is small, we find no evidence of a correlation between mass and
temperature in which white dwarfs below 13000K are systematically
more massive than those above this temperature. Within 20pc 25% of
the white dwarfs are in binary systems (including double degenerate
systems). Approximately 6% are double degenerates and 6.5% are
Sirius-like systems. The fraction of magnetic white dwarfs in the
local population is found to be 13%.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 76 122 The local sample of white dwarfs
table2.dat 58 122 Local sample: physical parameters
table3.dat 48 122 Local sample: distances
table4.dat 74 37 Possible white dwarfs within 20pc
refs.dat 146 36 References
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See also:
http://www.astronomy.villanova.edu/WDCatalog/index.html : WD Villanova catalog
J/ApJS/133/413 : BVRIJHK photometry of cool white dwarfs (Bergeron+, 2001)
J/A+A/378/556 : UVES/VLT spectra of white dwarfs (Koester+, 2001)
J/ApJ/571/512 : Distances of white dwarf stars (Holberg+, 2002)
J/ApJ/631/1100 : Atmospheric parameters of DA white dwarfs (Gianninas+, 2005)
J/ApJS/161/394 : Low-luminosity companions to white dwarfs (Farihi+, 2005)
J/ApJ/643/402 : Cool white dwarfs in the solar neighborhood (Kawka+, 2006)
J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)
J/ApJ/654/499 : H-rich white dwarfs spectropolarimetric survey (Kawka+, 2007)
J/AJ/134/252 : New nearby white dwarf systems (Subasavage+, 2007)
J/ApJ/663/1291 : DZ stars in SDSS DR4 (Dufour+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [WD]
4- 13 A10 --- WD WD number (HHMM+DDM.N, B1950)
14- 18 A5 --- n_WD [a-c, ] Note on WD (1)
20- 34 A15 --- OName Other name
36- 42 A7 --- SpType Spectral type
44- 49 F6.3 mag Vmag Visual magnitude
51- 56 F6.2 mas pi ?=- Trigonometric parallax
58- 62 F5.2 mas e_pi ?=- Parallaxe uncertainty
64- 68 A5 --- r_pi Reference(s) number for pi; see refs.dat file
70- 72 A3 --- Bin Binarity (2)
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Note (1): Flags as follows:
a = Not presently in the Villanova Catalog
(http://www.astronomy.villanova.edu/WDCatalog/, Cat. B/wd)
b = Preliminary trigonometric parallax indicates star well within 20pc
c = New entery (not in Holberg et al., 2002, Cat. J/ApJ/571/512, HOS)
Note (2): System as follows:
b = Binary or multiple system,
dd = double-degenerate system
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [WD]
4- 13 A10 --- WD WD designation (HHMM+DDM.N, B1950)
15- 16 A2 --- Comp Composition (He or H)
22- 26 I5 K Teff ?=- Effective temperature
28- 31 I4 K e_Teff ?=- Teff uncertainty
33- 37 F5.3 [cm/s2] logg ?=- Surface gravity
39- 43 F5.3 [cm/s2] e_logg ?=- logg uncertainty
45- 49 F5.3 Msun Mass ?=- Mass
51- 55 F5.3 Msun e_Mass ?=- Mass uncertainty
57- 58 I2 --- Ref ?=- Reference; see refs.dat file
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [WD]
4- 13 A10 --- WD WD designation (HHMM+DDM.N, B1950)
15- 19 F5.2 pc r.tr ?=- Trigonometric distance
21- 24 F4.2 pc e_r.tr ?=- r.tr uncertainty
26- 30 F5.2 pc r.ph ?=- Photometric distance
32- 35 F4.2 pc e_r.ph ?=- r.ph uncertainty
37- 41 F5.2 pc r ? Final adopted distance
43- 46 F4.2 pc e_r ? Adopted distance uncertainty
48 A1 --- n_r [a] Weighted mean of trigonometric
and photometric distance
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [WD]
4- 11 A8 --- WD WD designation (HHMM+DDM, B1950) (1)
13- 27 A15 --- OName Other name
29- 34 A6 --- SpType Spectral type
36- 40 F5.2 pc r.tr ?=- Trigonometric distance
42- 45 F4.2 pc e_r.tr ?=- r.tr uncertainty
47- 51 F5.2 pc r.ph Photometric distance
53- 56 F4.2 pc e_r.ph ?=- r.ph uncertainty
58- 62 A5 --- Ref reference(s) number; see refs.dat file
64- 69 F6.3 mag Vmag ?=- Visual magnitude
70 A1 --- u_Vmag Uncertainty flag on Vmag
72- 74 A3 --- Notes [a-c, ] Note(s) (2)
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Note (1): WD 0816+387 is the correct name of WD 0827+387 (in original paper)
WD 1339-340 PM J13420-3415 are the correct names for
WD 1339+259 PM J134020-3415 (in original table).
Note (2): Notes as follows:
a = Double degenerate;
b = binary;
c = photometric distances estimated in this paper.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode Bibcode
24- 49 A26 --- Aut Author's name(s)
51-146 A96 --- Com Comments
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 29-Jun-2010